Wrasse and lumpfish used as biological sea lice controls in salmon farming are receiving increasing welfare attention as their use has expanded dramatically without adequate welfare standards.
Cleaner fish welfare represents a striking case of welfare consideration lag — the regulatory and cultural framework treating these fish as biological tools rather than sentient animals with welfare needs, despite evidence of nociception and stress responses comparable to other fish. The extraordinary mortality rates — often the majority of deployed animals dying within the production cycle — would be considered a welfare crisis if the same rates applied to salmon. The welfare invisibility of cleaner fish is slowly being challenged by welfare scientists and some regulators, but the industry has expanded enormously with limited welfare accountability. The case for developing cleaner fish welfare standards is both ethically urgent and practically feasible.